1. Field of the Invention
The present invention relates to instruments for ligating anatomical tissue and, more particularly, to instrument assemblies for performing a complete anatomical tissue ligation procedure and to instruments for use in such assemblies.
2. Discussion of the Prior Art
Various operative procedures previously performed as open surgery requiring relatively large longitudinal incisions have come to be performed endoscopically. In endoscopic procedures, instruments are introduced at internal operative sites through relatively small, artificially created or natural openings providing communication with the internal operative sites from externally thereof. The instruments are manipulated remotely, from externally of the internal operative sites, to perform various operative procedures under visualization provided by an endoscope. Endoscopic procedures have many advantages over open surgical procedures including minimal invasiveness and trauma, shorter hospital stays and recovery times, minimal scarring and patient discomfort, fewer post-operative complications, lower cost and reduced risk for the patient.
Ligating anatomical tissue is a time consuming and tedious part of both endoscopic and open operative procedures due to the difficulty involved in applying an occluding ligature to anatomical tissue as is necessary and desirable in many various procedures. Ligating anatomical tissue is particularly difficult in endoscopic procedures due to the limited room for maneuverability at the internal operative site, the number of different instruments required and the complicated operative steps involved. In particular, separate instruments are required to grasp the anatomical tissue and to position and contract a ligature loop therearound to form a ligature. Furthermore, additional instruments are usually required to cut the ligated tissue as well as the material of the ligature loop. Accordingly, the advantages of endoscopic procedures are sometimes outweighed by the disadvantages caused by the length of time required to perform endoscopic procedures where such time is significantly extended due to the time required for tissue ligation.
Tubal ligation has become increasingly popular as an alternative to presently available contraceptives due to the various adverse complications, inconveniences and relatively high rates of failure associated with contraceptives. It is increasingly common for patients undergoing abdominal surgery for other reasons to request that a tubal ligation be performed at the same time. One technique of tubal ligation that is widely accepted due to its ease of execution, safety and reliability is the Pomeroy technique of tubal ligation. According to the Pomeroy technique, a Fallopian tube is grasped and drawn into a loop formation. The loop formation is ligated with a bioabsorbable ligature. A segment of the ligated loop formation is cut, creating ends extending from the ligature. During healing, the ends separate and occlude, thusly preventing recanalization. The procedure is repeated for the other Fallopian tube to prevent pregnancy. Since it is sometimes possible for another anatomical structure, such as the round ligament, to be mistaken for the Fallopian tube, the Pomeroy technique includes removing the cut segments of the loop formation from the patient's body for positive identification via biopsy. Where the cut segments are identified as being from the Fallopian tubes, proper tubal ligation is confirmed. Where one or both of the cut segments is identified as being from another anatomical structure, the patient can be so advised and, if feasible, surgical correction can be undertaken.
The use of endoscopic techniques for tubal ligation has been limited, however, by a lack of instrumentation and by procedural difficulties due to the limited room for access, maneuverability and visualization at the operative site and due to the need for various different instruments to be introduced at the operative site. The Pomeroy procedure, for example, has not been safely and efficiently performed as endoscopic or laparoscopic surgery. By increasing the safety and efficacy of endoscopic tubal ligation, endoscopic tubal ligation can be made available to patients undergoing other endoscopic operative procedures and can itself represent a viable, safe, cost-effective birth control option for patients not undergoing other endoscopic operative procedures.